Fuel cell vehicle with a water system

ABSTRACT

Embodiments of systems and methods of operating a vehicle include operating at least one fuel cell stack, whereupon a heat exchanger therefor the at least one fuel cell stack counter-balances heat therefrom with heat rejected therefrom, and operating a water system to pump water from the at least one fuel cell stack into a water reservoir. Moreover, in response to high water levels in the water reservoir, the embodiments include increasing electrical energy loads on at least one battery operable to store electrical energy from the at least one fuel cell stack, operating the at least one fuel cell stack for higher output, whereupon the heat exchanger under-balances heat therefrom with heat rejected therefrom, and operating the water system to apply water from the water reservoir onto the heat exchanger, whereupon the heat exchanger restoratively counter-balances heat therefrom with heat rejected therefrom.

TECHNICAL FIELD

The embodiments disclosed herein relate to vehicles and, moreparticularly, to vehicles that have electrified powertrains.

BACKGROUND

Many vehicles are electrified vehicles or, in other words, vehicles thathave electrified powertrains. The typical electrified vehicle has a moreor less traditional drivetrain. Specifically, as part of the drivetrain,the electrified vehicle includes one or more wheels, as well as atransmission, a differential, a drive shaft and the like, to which thewheels are mechanically connected. However, in place of an engine, theelectrified vehicle includes one or more motors. And, as part of theelectrified powertrain, the drivetrain is mechanically connected to themotors. In conjunction with the drivetrain, the motors are operable topower the wheels using electrical energy.

Many electrified vehicles are, moreover, fuel cell vehicles (FCVs) or,in other words, electrified vehicles that include one or more fuel cellstacks. In the typical FCV, the fuel cell stacks are operable togenerate electrical energy, including the electrical energy used by themotors to power the wheels. In addition to being operable to generateelectrical energy, the fuel cell stacks are operable to generate water.

SUMMARY

Disclosed herein are embodiments of systems and methods of operating avehicle that includes a fuel cell stack and elements of a water systemfor reclaiming water from the fuel cell stack for dispensation. In oneaspect, the embodiments include operating at least one fuel cell stack,whereupon a heat exchanger for the at least one fuel cell stackcounter-balances heat from the at least one fuel cell stack with heatrejected from the at least one fuel cell stack, and operating a watersystem to pump water from the at least one fuel cell stack into a waterreservoir. Moreover, in response to high water levels in the waterreservoir, the embodiments include increasing electrical energy loads onat least one battery operable to store electrical energy from the atleast one fuel cell stack, operating the at least one fuel cell stackfor higher output, whereupon the heat exchanger under-balances heat fromthe at least one fuel cell stack with heat rejected from the at leastone fuel cell stack, and operating the water system to apply water fromthe water reservoir onto the heat exchanger, whereupon the heatexchanger restoratively counter-balances heat from the at least one fuelcell stack with heat rejected from the at least one fuel cell stack.This and other aspects will be described in additional detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features, advantages and other uses of the presentembodiments will become more apparent by referring to the followingdetailed description and drawing in which:

FIG. 1 is a portrayal of a fuel cell vehicle (FCV) using a communicativeblock diagram and perspective views, showing a body, a chassis, vehiclesystems, a sensor system and a control module, with the vehicle systemsincluding an energy system, including a fuel cell system, a batterysystem and a fuel tank system therein, a propulsion system, including amotor system therein, auxiliary systems and a water system;

FIGS. 2A and 2B are portrayals of the FCV using an electrical blockdiagram and a fluid and pneumatic schematic diagram, further showing thefuel cell system, including a fuel cell stack and a heat exchanger forthe fuel cell stack in the fuel cell system, the fuel tank system,including fuel tanks and a fuel piping network for the fuel tanks in thefuel tank system, and the water system, including a water collector, awater pump and a water reservoir in the water system for reclaimingwater from the fuel cell stack for dispensation, and water pumps in thewater system for applying water from the water reservoir onto the heatexchanger and otherwise dispensing water from the water reservoir; and

FIG. 3 is a flowchart showing the operations of a process by which thecontrol module orchestrates the operation of the FCV.

DETAILED DESCRIPTION

This disclosure teaches a vehicle that includes a fuel cell stack and awater system for reclaiming water from the fuel cell stack fordispensation. The fuel cell stack generates electrical energy and water.In addition to the fuel cell stack and the water system, the vehicleincludes a heat exchanger for rejecting heat from the fuel cell stack,and one or more batteries for storing electrical energy from the fuelcell stack. The water system pumps water from the fuel cell stack into awater reservoir, applies water from the water reservoir onto the heatexchanger, whereupon the heat exchanger super-normally rejects heat fromthe fuel cell stack, and evacuates water from the water reservoir. Whenwater levels in the water reservoir are high, and the heat exchangercounter-balances heat from the fuel cell stack with heat rejected fromthe fuel cell stack, instead of the water system wastefully evacuatingwater from the water reservoir, electrical energy loads on the batteriesare increased. In association with increasing electrical energy loads onthe batteries, the fuel cell stack operates for higher output, whereuponthe heat exchanger under-balances heat from the fuel cell stack withheat rejected from the fuel cell stack, and the water system applieswater from the water reservoir onto the heat exchanger, whereupon theheat exchanger restoratively counter-balances heat from the fuel cellstack with heat rejected from the fuel cell stack.

A fuel cell vehicle (FCV) 100 is shown in FIG. 1. In this description,uses of “front,” “forward” and the like, and uses of “rear,” “rearward”and the like, refer to the longitudinal directions of the FCV 100.“Front,” “forward” and the like refer to the front (fore) of the FCV100, while “rear,” “rearward” and the like refer to the back (aft) ofthe FCV 100. Uses of “side,” “sideways,” “transverse” and the like referto the lateral directions of the FCV 100, with “driver's side” and thelike referring to the left side of the FCV 100, and “passenger side” andthe like referring to the right side of the FCV 100.

The FCV 100 is a semi-tractor or, in other words, a tractor unit that,together with a hitched semitrailer 102, forms a semi-truck. The FCV 100has an exterior 104 and a number of interior compartments. Thecompartments include a passenger compartment 106, a front compartment108 forward of the passenger compartment 106 and a rear compartment 110rearward of the passenger compartment 106. The FCV 100 may include,among other things, seats and a dash assembly housed in the passengercompartment 106.

The FCV 100 has a body 112 that forms the exterior 104 and defines thecompartments. The body 112 has upright sides, a floor, a front end, arear end, a roof and the like. In the semi-truck to which the FCV 100belongs, the semitrailer 102 similarly has an exterior and, as aninterior compartment, a cargo compartment for carrying cargo. Inaddition to the body 112, the FCV 100 has a chassis 114. The chassis 114serves as an underbody for the FCV 100. The chassis 114, like the body112, forms the exterior 104. As part of the chassis 114, the FCV 100includes a hitch 116 for hitching the semitrailer 102 to the FCV 100.With the semitrailer 102 hitched to the FCV 100, the FCV 100 is operableto pull the semitrailer 102 and any onboard cargo.

The FCV 100 has a drivetrain. The drivetrain is part of, mounted to orotherwise supported by the chassis 114. The drivetrain may be housed, inwhole or in part, in any combination of the chassis 114, the frontcompartment 108, the rear compartment 110 or elsewhere in the FCV 100.As part of the drivetrain, the FCV 100 includes wheels 118. The wheels118 support the remainder of the FCV 100 on the ground. The FCV 100includes ten wheels 118, two of which are front wheels 118A, and eightof which are rear wheels 118B. The rear wheels 118B are arranged in fourdual-wheel setups. One, some or all of the wheels 118 are powered todrive the FCV 100 along the ground. In a rear-wheel drive arrangement,one, some or all of the rear wheels 118B are powered to drive the FCV100 along the ground. For this purpose, also as part of the drivetrain,in addition to the wheels 118, the FCV 100 includes any penultimatecombination of a transmission, a differential, a drive shaft and thelike, to which the wheels 118 are mechanically connected.

The FCV 100 operates as an assembly of interconnected items that equipthe FCV 100 to satisfy real-time vehicle demands. Generally speaking, avehicle demand corresponds to a vehicle function whose performancesatisfies the vehicle demand. Accordingly, the FCV 100 is equipped, inoperation, to satisfy one or more vehicle demands by performing one ormore corresponding vehicle functions. With respect to performing vehiclefunctions, the FCV 100 is subject to any combination of manual operationand autonomous operation. In the case of manual operation, the FCV 100may be manual-only. In the case of autonomous operation, the FCV 100 maybe semi-autonomous, highly-autonomous or fully-autonomous.

For purposes of satisfying vehicle demands, the FCV 100 includes one ormore vehicle systems 120. Either alone or in conjunction with thedrivetrain, the vehicle systems 120 are operable to perform vehiclefunctions on behalf of the FCV 100, and thereby satisfy correspondingvehicle demands on behalf of the FCV 100. Any combination of the vehiclesystems 120 may be operable to perform a vehicle function. Accordingly,from the perspective of a vehicle function, as well as a correspondingvehicle demand, one, some or all of the vehicle systems 120 serve asassociated vehicle systems 120. Moreover, each vehicle system 120 may beoperable to perform any combination of vehicle functions, and therebysatisfy any combination of corresponding vehicle demands, in whole or inpart. Accordingly, each vehicle system 120, from its own perspective,serves as an associated vehicle system 120 for one or more vehiclefunctions, as well as one or more corresponding vehicle demands.

In addition to the vehicle systems 120, the FCV 100 includes a sensorsystem 122, as well as one or more processors 124, memory 126, and acontrol module 128 to which the vehicle systems 120 and the sensorsystem 122 are communicatively connected. The sensor system 122 isoperable to detect information about the FCV 100. The processors 124,the memory 126 and the control module 128 together serve as a computingdevice whose control module 128 orchestrates the operation of the FCV100, in whole or in part. Specifically, the control module 128 operatesthe vehicle systems 120 based on information about the FCV 100.Accordingly, as a prerequisite to operating the vehicle systems 120, thecontrol module 128 gathers information about the FCV 100, including theinformation about the FCV 100 detected by the sensor system 122. Thecontrol module 128 then evaluates the information about the FCV 100, andoperates the vehicle systems 120 based on its evaluation. As part of itsevaluation of the information about the FCV 100, the control module 128identifies one or more vehicle demands. Relatedly, as part of itsoperation of the vehicle systems 120, when a vehicle demand isidentified, the control module 128 operates one or more associatedvehicle systems 120 to satisfy the vehicle demand.

The vehicle systems 120 are part of, mounted to or otherwise supportedby the chassis 114. The vehicle systems 120 may be housed, in whole orin part, in any combination of the chassis 114, the passengercompartment 106, the front compartment 108, the rear compartment 110 orelsewhere in the FCV 100. Each vehicle system 120 includes one or morevehicle elements. On behalf of the vehicle system 120 to which itbelongs, each vehicle element is operable to perform, in whole or inpart, any combination of vehicle functions with which the vehicle system120 is associated. It will be understood that the vehicle elements, aswell as the vehicle systems 120 to which they belong, may but need notbe mutually distinct.

The vehicle systems 120 include an energy system 130 and a propulsionsystem 132. The energy system 130 and the propulsion system 132 areelectrically connected to one another. Moreover, the drivetrain ismechanically connected to the propulsion system 132. The propulsionsystem 132 and the drivetrain together serve as an electrifiedpowertrain for the FCV 100. The energy system 130 is operable to performone or more energy functions, including but not limited to generatingelectrical energy and generating water. The propulsion system 132 isoperable to perform one or more propulsion functions using electricalenergy from the energy system 130, including but not limited to poweringthe wheels 118.

Specifically, the energy system 130 is operable to generate electricalenergy, store electrical energy, condition and otherwise handleelectrical energy, and store and otherwise handle fuel. In conjunctionwith the drivetrain, the propulsion system 132 is operable to power thewheels 118 using electrical energy from the energy system 130. With thewheels 118 powered, the propulsion system 132 is employable toaccelerate the FCV 100, maintain the speed of the FCV 100 (e.g., onlevel or uphill ground) and otherwise drive the FCV 100 along theground. The propulsion system 132 is also operable to generateelectrical energy using one, some or all of the wheels 118, andconsequently retard the wheels 118. With the wheels 118 retarded, thepropulsion system 132 is employable to decelerate the FCV 100, maintainthe speed of the FCV 100 (e.g., on downhill ground) and otherwise drivethe FCV 100 along the ground. The energy system 130, in turn, isoperable to store electrical energy from the propulsion system 132. Asthe combined product of generating electrical energy, and consequentlyretarding the wheels 118, and storing electrical energy, the propulsionsystem 132 and the energy system 130 are operable to regenerativelybrake the FCV 100 at the wheels 118.

In addition to the energy system 130 and the propulsion system 132, thevehicle systems 120 include one or more auxiliary systems 134 and awater system 136. The auxiliary systems 134 include a braking system140, a steering system 142 and an accessory system 144. The auxiliarysystems 134 and the water system 136, like the propulsion system 132,are electrically connected to the energy system 130. Moreover, the watersystem 136 is fluidly connected to the energy system 130. The auxiliarysystems 134 are operable to perform one or more auxiliary functionsusing electrical energy from the energy system 130, including but notlimited to frictionally braking the FCV 100, steering the FCV 100 andone or more accessory functions. The water system 136 is operable toperform one or more water functions using electrical energy and waterfrom the energy system 130, including but not limited to reclaiming,dispensing and otherwise handling water from the energy system 130.Accordingly, although the propulsion system 132 acts as the principalelectrical energy load on the energy system 130, the auxiliary systems134 and the water system 136 act as electrical energy loads on theenergy system 130 as well. Moreover, in addition to acting as anelectrical energy load on the energy system 130, the water system 136acts as a water load on the energy system 130.

As part of the sensor system 122, the FCV 100 includes one or moreonboard sensors. The sensors monitor the FCV 100 in real-time. Thesensors, on behalf of the sensor system 122, are operable to detectinformation about the FCV 100, including information about user requestsand information about the operation of the FCV 100.

The FCV 100 includes user controls. The user controls serve asinterfaces between users of the FCV 100 and the FCV 100 itself, and areoperable to receive mechanical, verbal and other user inputs requestingvehicle functions. In conjunction with corresponding user controls, andamong the sensors, the FCV 100 includes an accelerator pedal sensor, abrake pedal sensor, a steering angle sensor and the like, and one ormore selector sensors, one or more microphones, one or more cameras andthe like. Relatedly, among information about user requests, the sensorsystem 122 is operable to detect user inputs requesting powering thewheels 118, user inputs requesting braking, steering and the like, userinputs requesting accessory functions, and user inputs requesting waterfunctions.

Also among the sensors, the FCV 100 includes one or more speedometers,one or more gyroscopes, one or more accelerometers, one or more wheelsensors, one or more inertial measurement units (IMUs), one or morecontroller area network (CAN) sensors and the like. Relatedly, amonginformation about the operation of the FCV 100, the sensor system 122 isoperable to detect the location and motion of the FCV 100, including itsspeed, acceleration, orientation, rotation, direction and the like, themovement of the wheels 118, and the operational statuses of one, some orall of the vehicle systems 120.

The energy system 130 includes a fuel cell system 150, a battery system152 and a fuel tank system 154. The propulsion system 132 includes amotor system 156. The motor system 156 is electrically connected to thefuel cell system 150. Moreover, the battery system 152 and the fuel cellsystem 150 are electrically connected to one another, and the motorsystem 156 and the battery system 152 are electrically connected to oneanother. Moreover, the fuel cell system 150 is fluidly connected to thefuel tank system 154. The fuel cell system 150 is operable to generateelectrical energy and water using electrical energy from the batterysystem 152 and fuel from the fuel tank system 154. In conjunction withthe drivetrain, the motor system 156 is operable to power the wheels 118using electrical energy from any combination of the fuel cell system 150and the battery system 152. The motor system 156 is also operable togenerate electrical energy using the wheels 118, and consequently retardthe wheels 118. The battery system 152 is operable to store electricalenergy from the fuel cell system 150. The battery system 152 is alsooperable to store electrical energy from the motor system 156. The fueltank system 154 is operable to store and otherwise handle fuel,including fueling the fuel cell system 150 with fuel.

As shown with additional reference to FIGS. 2A and 2B, in addition tothe fuel cell system 150, the battery system 152 and the fuel tanksystem 154, the energy system 130 includes a junction box 200 andattendant energy elements. The motor system 156 is electricallyconnected to the fuel cell system 150 through the junction box 200.Moreover, the battery system 152 and the fuel cell system 150 areelectrically connected to one another through the junction box 200, andthe motor system 156 and the battery system 152 are electricallyconnected to one another through the junction box 200.

The FCV 100 includes one or more energy elements as part of the fuelcell system 150. Among the energy elements of the fuel cell system 150,the FCV 100 includes a fuel cell stack 202. Although the FCV 100, asshown, includes one fuel cell stack 202 in the fuel cell system 150, itwill be understood that this disclosure is applicable in principle tootherwise similar vehicles including multiple fuel cell stacks 202 inthe fuel cell system 150. In relation to the fuel cell stack 202, amongthe attendant energy elements of the energy system 130, the FCV 100includes a fuel cell converter 204. The fuel cell converter 204 iselectrically connected to the fuel cell stack 202. The fuel cell stack202 is operable to generate electrical energy. The fuel cell converter204 is operable to condition electrical energy from the fuel cell stack202. Specifically, the fuel cell converter 204 is a DC/DC converteroperable to convert lower voltage DC electrical energy from the fuelcell stack 202 into higher voltage DC electrical energy. For instance,the lower voltage DC electrical energy may be medium voltage DCelectrical energy (e.g., approximately 370 VDC), and the higher voltageDC electrical energy may be high voltage DC electrical energy (e.g.,approximately 650 VDC).

The FCV 100 also includes one or more propulsion elements as part of themotor system 156. Among the propulsion elements of the motor system 156,the FCV 100 includes a motor 206. Although the FCV 100, as shown,includes one motor 206 in the motor system 156, it will be understoodthat this disclosure is applicable in principle to otherwise similarvehicles including multiple motors 206 in the motor system 156. Themotor 206 is a synchronous three-phase AC electric motor. In relation tothe motor 206, among the attendant energy elements of the energy system130, the FCV 100 includes a motor inverter 208. The motor inverter 208is electrically connected to the fuel cell converter 204 through thejunction box 200, and the motor 206 is electrically connected to themotor inverter 208. Moreover, the drivetrain is mechanically connectedto the motor 206. The motor inverter 208 is operable to conditionelectrical energy from the fuel cell converter 204. Specifically, themotor inverter 208 is operable to convert DC electrical energy from thefuel cell converter 204 into three-phase AC electrical energy. Forinstance, the three-phase AC electrical energy may be high voltage ACelectrical energy (e.g., approximately 650 VAC). In conjunction with thedrivetrain, the motor 206 is operable to power the wheels 118 usingelectrical energy from the motor inverter 208.

The FCV 100 also includes one or more energy elements as part of thebattery system 152. Among the energy elements of the battery system 152,the FCV 100 includes one or more batteries 210. Although the FCV 100, asshown, includes two batteries 210 in the battery system 152, it will beunderstood that this disclosure is applicable in principle to otherwisesimilar vehicles including one battery 210 in the battery system 152, aswell as otherwise similar vehicles otherwise including multiplebatteries 210 in the battery system 152. In relation to the batteries210, among the attendant energy elements of the energy system 130, theFCV 100 includes a battery converter 212. From the perspective of thefuel cell system 150, the battery converter 212 is electricallyconnected to the fuel cell converter 204 through the junction box 200,and the batteries 210 are electrically connected to the batteryconverter 212 through the junction box 200. The battery converter 212 isoperable to condition electrical energy from the fuel cell converter204. Specifically, the battery converter 212 is a DC/DC converteroperable to convert higher voltage DC electrical energy from the fuelcell converter 204 into lower voltage DC electrical energy. Forinstance, the higher voltage DC electrical energy may be high voltage DCelectrical energy (e.g., approximately 650 VDC), and the lower voltageDC electrical energy may be medium voltage DC electrical energy (e.g.,approximately 288 VDC). The batteries 210 are operable to storeelectrical energy from the battery converter 212.

Also, from the perspective of the battery system 152, the batteryconverter 212 is electrically connected to the batteries 210 through thejunction box 200, the motor inverter 208 is electrically connected tothe battery converter 212 through the junction box 200 and, as notedabove, the motor 206 is electrically connected to the motor inverter208. Relatedly, the battery converter 212 is also operable to conditionelectrical energy from the batteries 210. Specifically, the batteryconverter 212 is a DC/DC converter operable to convert lower voltage DCelectrical energy from the batteries 210 into higher voltage DCelectrical energy. For instance, the lower voltage DC electrical energymay be medium voltage DC electrical energy (e.g., approximately 288VDC), and the higher voltage DC electrical energy may be high voltage DCelectrical energy (e.g., approximately 650 VDC). The motor inverter 208is also operable to condition electrical energy from the batteryconverter 212. Specifically, the motor inverter 208 is operable toconvert DC electrical energy from the battery converter 212 intothree-phase AC electrical energy. As noted above, the three-phase ACelectrical energy may be high voltage AC electrical energy (e.g.,approximately 650 VAC). Once again, in conjunction with the drivetrain,the motor 206 is operable to power the wheels 118 using electricalenergy from the motor inverter 208.

Similarly, from the perspective of the motor system 156, the motorinverter 208 is electrically connected to the motor 206, the batteryconverter 212 is electrically connected to the motor inverter 208through the junction box 200 and, as noted above, the batteries 210 areelectrically connected to the battery converter 212 through the junctionbox 200. Relatedly, in conjunction with the drivetrain, the motor 206 isalso operable to generate electrical energy using the wheels 118, andconsequently retard the wheels 118. Moreover, the motor inverter 208 isalso operable to condition electrical energy from the motor 206.Specifically, the motor inverter 208 is operable to convert three-phaseAC electrical energy from the motor 206 into DC electrical energy. Forinstance, the three-phase AC electrical energy may be high voltage ACelectrical energy (e.g., approximately 650 VAC), and the DC electricalenergy may be high voltage DC electrical energy (e.g., approximately 650VDC). The battery converter 212 is also operable to condition electricalenergy from the motor inverter 208 in the same manner as electricalenergy from the fuel cell converter 204. Once again, the batteries 210are operable to store electrical energy from the battery converter 212.As the combined product of generating electrical energy, consequentlyretarding the wheels 118 and storing electrical energy, the motor 206and the batteries 210 are operable to regeneratively brake the FCV 100at the wheels 118.

Among other things, it follows that the motor 206 is operable to powerthe wheels 118 using electrical energy from any combination of the fuelcell stack 202 and the batteries 210. Moreover, the batteries 210 areoperable to store electrical energy from any combination of the fuelcell stack 202 and the motor 206. In a fuel cell stack-poweredimplementation, the motor 206 principally powers the wheels 118 usingelectrical energy from the fuel cell stack 202. When the fuel cell stack202 generates surplus electrical energy, the motor 206 powers the wheels118 using some electrical energy from the fuel cell stack 202, and thebatteries 210 store some electrical energy from the fuel cell stack 202.Otherwise, the motor 206 powers the wheels 118 using all electricalenergy from the fuel cell stack 202, and the batteries 210 store noelectrical energy from the fuel cell stack 202. Moreover, when the fuelcell stack 202 generates insufficient electrical energy, the motor 206powers the wheels 118 using not only all electrical energy from the fuelcell stack 202, but also some electrical energy from the batteries 210.Absent the fuel cell stack 202 generating surplus electrical energy whenthe motor 206 powers the wheels 118, the batteries 210 principally storeelectrical energy from the motor 206 when the motor 206 generateselectrical energy using the wheels 118, and consequently retards thewheels 118.

Also among the attendant energy elements of the energy system 130, theFCV 100 includes one or more handling units 214. The handling units 214are electrically connected to the batteries 210 through the junction box200. The handling units 214 may include one or more power supplies(e.g., one or more DC power supplies), one or more inverters, one ormore converters (e.g., one or more DC/DC converters) and the like. Thehandling units 214 are operable to condition and otherwise handleelectrical energy from the batteries 210, including but not limited todistributing electrical energy from the batteries 210 and conditioningelectrical energy from the batteries 210 (e.g., converting DC electricalenergy from the batteries 210 into three-phase AC electrical energy,converting higher voltage DC electrical energy from the batteries 210into lower voltage DC electrical energy, etc.).

As noted above, the FCV 100 includes the fuel cell stack 202 among theenergy elements of the fuel cell system 150. Also among the energyelements of the fuel cell system 150, the FCV 100 includes a fuel pump216 and an air compressor 218. The fuel pump 216 and the air compressor218 are electrically connected to the handling units 214. Moreover, thefuel pump 216 is fluidly connected to the fuel tank system 154, and thefuel cell stack 202 is fluidly connected to the fuel pump 216. Moreover,in addition to being fluidly connected to the fuel pump 216, the fuelcell stack 202 is pneumatically connected to the air compressor 218. Thefuel pump 216 is operable to pump fuel from the fuel tank system 154into the fuel cell stack 202 using electrical energy from the handlingunits 214. The air compressor 218 is operable to pump air into the fuelcell stack 202 using electrical energy from the handling units 214.

The fuel cell stack 202 includes multiple fuel cells arranged in astacked setup. Employing the fuel cells, the fuel cell stack 202 isoperable to execute an electrochemical reaction that combines fuel withoxygen in air, and generates electrical energy. As a byproduct ofgenerating electrical energy, the electrochemical reaction generateswater. Moreover, also as a byproduct of generating electrical energy,the electrochemical reaction generates heat. Accordingly, in conjunctionwith the fuel pump 216 and the air compressor 218, as the product ofexecuting the electrochemical reaction, the fuel cell stack 202 isoperable to generate electrical energy and water, as well as heat. Asthe product of generating heat, the fuel cell stack 202 vaporizes somewater in the fuel cell stack 202, including water from the fuel cellstack 202.

In a hydrogen-fueled implementation, the fuel is hydrogen. In the fuelcell stack 202, each fuel cell includes an anode and a cathode. In thefuel cells, hydrogen from the fuel pump 216 is pumped to the anodeswhere, as part of the electrochemical reaction, hydrogen molecules areactivated by anode catalysts. Activated hydrogen molecules therebyrelease electrons, and become hydrogen ions. Released electrons travelfrom the anodes to the cathodes, thereby generating electrical current.In the fuel cell stack 202, electrical current generated by the fuelcells serves as electrical energy generated by the fuel cell stack 202.In the fuel cells, hydrogen ions also travel from the anodes to thecathodes. Oxygen in air from the air compressor 218 is pumped to thecathodes where, as part of the electrochemical reaction, hydrogen ionsbond with oxygen on cathode catalysts to generate water. In the fuelcell stack 202, water generated by the fuel cells is a byproduct ofgenerating electrical energy, and serves as water generated by the fuelcell stack 202.

The FCV 100 also includes one or more energy elements as part of thefuel tank system 154. Among the energy elements of the fuel tank system154, the FCV 100 includes one or more fuel tanks 220, as well as a fuelpiping network 222 for the fuel tanks 220. Although the FCV 100, asshown, includes two fuel tanks 220 in the fuel tank system 154, it willbe understood that this disclosure is applicable in principle tootherwise similar vehicles including one fuel tank 220 in the fuel tanksystem 154, as well as otherwise similar vehicles otherwise includingmultiple fuel tanks 220 in the fuel tank system 154. The fuel tanks 220are operable to store fuel. From the perspective of the fuel tanks 220,the fuel piping network 222 has a fuel input line 224 and a fuel outputline 226. In the hydrogen-fueled implementation, the fuel is hydrogen.Relatedly, each fuel tank 220 is a high-pressure hydrogen tank, andoperable to store high-pressure hydrogen, and the fuel piping network222 is a high-pressure hydrogen piping network.

The fuel input line 224 leads to the fuel tanks 220. On the fuel inputline 224, in addition to the requisite piping, the fuel piping network222 includes a fuel valve 228. The fuel valve 228 is fluidly connectableto a fueling station's fueling line, and each fuel tank 220 is fluidlyconnected to the fuel valve 228. The fuel valve 228 is operable toselectively open or close the fuel input line 224 to one, some or all ofthe fuel tanks 220. With the fuel valve 228 fluidly connected to afueling line, as the product of opening the fuel input line 224 to one,some or all of the fuel tanks 220, the fuel valve 228 is operable toopen a fluid connection from the fueling line to one, some or all of thefuel tanks 220. From the perspective of each fuel tank 220, with a fluidconnection opened from the fueling line to the fuel tank 220, the fuelpiping network 222 is employable to fill the fuel tank 220 with fuelfrom the fueling line. Moreover, with a fluid connection opened from thefueling line to multiple fuel tanks 220, the fuel piping network 222 isemployable to simultaneously fill the fuel tanks 220 with fuel from thefueling line.

The fuel output line 226 leads from the fuel tanks 220 to the fuel cellsystem 150. On the fuel output line 226, in addition to the requisitepiping, the fuel piping network 222 includes a fuel regulator 230. Thefuel regulator 230 is fluidly connected to each fuel tank 220, and thefuel cell system 150, at the fuel pump 216, is fluidly connected to thefuel regulator 230. The fuel regulator 230 is operable to selectivelyopen or close the fuel output line 226 from one, some or all of the fueltanks 220. Moreover, the fuel regulator 230 is operable to regulate theproperties of fuel in the fuel output line 226. Specifically, the fuelregulator 230 is a pressure regulator operable to regulate the pressureof fuel in the fuel output line 226. As the product of opening the fueloutput line 226 from one, some or all of the fuel tanks 220, the fuelregulator 230 is operable to open a fluid connection from one, some orall of the fuel tanks 220 to the fuel cell system 150. From theperspective of each fuel tank 220, with a fluid connection opened fromthe fuel tank 220 to the fuel cell system 150, the fuel piping network222 is employable to fuel the fuel cell system 150 with fuel from thefuel tank 220. Moreover, with a fluid connection opened from multiplefuel tanks 220 to the fuel cell system 150, the fuel piping network 222is employable to simultaneously fuel the fuel cell system 150 with fuelfrom the fuel tanks 220.

As noted above, the fuel cell stack 202 is operable to generate heat.Relatedly, also among the energy elements of the fuel cell system 150,the FCV 100 includes a coolant pump 232, a fan 234 and a coolant-to-airheat exchanger 236 for the fuel cell stack 202. The coolant pump 232 andthe heat exchanger 236 belong to a coolant circuit 238 that, in additionto the coolant pump 232 and the heat exchanger 236, includes the fuelcell stack 202. The heat exchanger 236 includes one or more radiatorsand the like. The coolant pump 232 and the fan 234 are electricallyconnected to the handling units 214. The coolant pump 232 is operable tocirculate water or other coolant in the coolant circuit 238 usingelectrical energy from the handling units 214. The fan 234 is operableto induce airflow across the heat exchanger 236 using electrical energyfrom the handling units 214. The heat exchanger 236 is operable toreject heat from coolant passing through the heat exchanger 236 toairflow across the heat exchanger 236. The fuel cell stack 202 isoperable to reject heat from the fuel cell stack 202 to coolant passingthrough the fuel cell stack 202. In conjunction with the coolant circuit238, the coolant pump 232, the fan 234 and the fuel cell stack 202, asthe product of rejecting heat from coolant passing through the heatexchanger 236 to airflow across the heat exchanger 236, the heatexchanger 236 is operable to reject heat from the fuel cell stack 202.

The auxiliary systems 134 are electrically connected to battery system152 through the junction box 200. The FCV 100 includes one or moreauxiliary elements as part of the braking system 140. Among theauxiliary elements of the braking system 140, the FCV 100 includes anair compressor 240, as well as one or more friction brakes at one, someor all of the wheels 118. The air compressor 240 is electricallyconnected to the handling units 214. The friction brakes arepneumatically connected to the air compressor 240, and the wheels 118are mechanically connected to the friction brakes. The air compressor240 is operable to pump air into the friction brakes using electricalenergy from the handling units 214. The friction brakes are operable tofrictionally brake the FCV 100 at the wheels 118 using air from the aircompressor 240.

The FCV 100 also includes one or more auxiliary elements as part of thesteering system 142. Among the auxiliary elements of the steering system142, the FCV 100 includes a fluid pump 242, as well as one or moresteering mechanisms at one, some or all of the wheels 118. The fluidpump 242 is electrically connected to the handling units 214. Thesteering mechanisms are hydraulically connected to the fluid pump 242,and the wheels 118 are mechanically connected to the steeringmechanisms. The fluid pump 242 is operable to pump power steering fluidinto the steering mechanisms using electrical energy from the handlingunits 214. The steering mechanisms are operable to adjust the steeringangle of the wheels 118 using power steering fluid from the fluid pump242. In a front-wheel steer arrangement, one steering system 142 isoperable to adjust the steering angle of both front wheels 118A usingpower steering fluid from the fluid pump 242. In conjunction with thefluid pump 242, as the product of adjusting the steering angle of thewheels 118, the steering mechanisms are operable to steer the FCV 100 asit drives along the ground.

The FCV 100 also includes one or more auxiliary elements as part of theaccessory system 144. Among the auxiliary elements of the accessorysystem 144, the FCV 100 includes one or more accessories 244. Theaccessories 244 are typical of vehicles, and include any combination ofone or more interior lights, one or more exterior lights, one or moregauges, one or more infotainment systems, one or more navigation systemsand the like. The accessories 244 are electrically connected to thehandling units 214. The accessories 244 are operable to illuminate theFCV 100, signal driving intentions, deliver information about theoperation of the FCV 100, deliver infotainment content to users of theFCV 100, establish routes and directions for the FCV 100, and otherwiseperform accessory functions using electrical energy from the handlingunits 214.

As noted above, the FCV 100 includes the fuel cell stack 202 among theenergy elements of the fuel cell system 150. Also among the energyelements of the fuel cell system 150, the FCV 100 includes an exhaust246 for the fuel cell stack 202. The exhaust 246 is fluidly connected tothe fuel cell stack 202, and opens outside the fuel cell stack 202. Theexhaust 246 is operable to exhaust water, including, among other water,vaporized water, from the fuel cell stack 202.

The water system 136 is fluidly connected to the fuel cell stack 202 atthe exhaust 246. Downstream of the exhaust 246, the FCV 100 includes oneor more water elements as part of the water system 136. Among the waterelements of the water system 136, the FCV 100 includes a water collector250 and a water reservoir 252, as well as a water piping network 254 forthe water collector 250 and the water reservoir 252. The water pipingnetwork 254 includes a water discharge line 256, a water storage line258, a water evacuation line 260 and one or more water dispensationlines 262.

The water collector 250 is fluidly connected to the exhaust 246. Inconjunction with the exhaust 246, the water collector 250 is operable tocollect water from the fuel cell stack 202. In association withcollecting water from the fuel cell stack 202, the water collector 250is operable to de-vaporize vaporized water from the fuel cell stack 202for collection in the water collector 250. For instance, in a watercondensation implementation, the water collector 250 includes a heatsink. The heat sink is operable to reject heat from vaporized water inthe water collector 250 to airflow around the water collector 250. Asthe product of rejecting heat from vaporized water in the watercollector 250, the heat sink is operable to condense vaporized water forcollection in the water collector 250. Additionally, or alternatively,in a water knockout implementation, the water collector 250 includes avapor-liquid separator. The vapor-liquid separator is operable to removewater from vaporized water in the water collector 250. As the product ofremoving water from vaporized water in the water collector 250, thevapor-liquid separator is operable to remove water from vaporized waterfor collection in the water collector 250.

The water discharge line 256 leads from the water collector 250 tooutside the water collector 250. Specifically, the water discharge line256 leads to the environment surrounding the FCV 100. On the waterdischarge line 256, in addition to the requisite piping, the waterpiping network 254 includes a water valve 264. The water valve 264 isfluidly connected to the water collector 250. The water valve 264 isoperable to selectively open or close the water discharge line 256 fromthe water collector 250. As the product of opening the water dischargeline 256 from the water collector 250, the water valve 264 is operableto discharge water from the water collector 250, including discharging,among other water, vaporized water from the water collector 250. Forinstance, the water valve 264 is operable to discharge water from thewater collector 250 when water levels in the water collector 250 are toohigh. Moreover, with the exhaust 246 fluidly connected to the fuel cellstack 202, and the water collector 250 fluidly connected to the exhaust246, as the product of discharging vaporized water from the watercollector 250, the water valve 264 is operable to relieve or otherwiseregulate backpressure in the fuel cell stack 202 associated withvaporized water in the water collector 250.

The water storage line 258 leads from the water collector 250 to thewater reservoir 252. On the water storage line 258, in addition to therequisite piping, the water piping network 254 includes a water pump266. The water pump 266 is electrically connected to the handling units214. Moreover, the water pump 266 is fluidly connected to the watercollector 250, and the water reservoir 252 is fluidly connected to thewater pump 266. The water pump 266 is operable to pump water from thewater collector 250 into the water reservoir 252 using electrical energyfrom the handling units 214. The water reservoir 252 is operable tostore water. Accordingly, in conjunction with the exhaust 246 and thewater collector 250, the water pump 266 is operable to pump water fromthe fuel cell stack 202 into the water reservoir 252 for storage.Likewise, the water reservoir 252 is operable to store water from thefuel cell stack 202 for dispensation onboard the FCV 100. As thecombined product of collecting water from the fuel cell stack 202,pumping water from the fuel cell stack 202 into the water reservoir 252for storage, and storing water from the fuel cell stack 202, the watercollector 250, the water pump 266 and the water reservoir 252 areoperable to reclaim water from the fuel cell stack 202 for dispensationonboard the FCV 100.

The water evacuation line 260 leads from the water reservoir 252 tooutside the water reservoir 252. Specifically, the water evacuation line260 leads to the environment surrounding the FCV 100. On the waterevacuation line 260, in addition to the requisite piping, the waterpiping network 254 includes a water valve 268. The water valve 268 isfluidly connected to the water reservoir 252. The water valve 268 isoperable to selectively open or close the water evacuation line 260 fromthe water reservoir 252. As the product of opening the water evacuationline 260 from the water reservoir 252, the water valve 268 is operableto evacuate water from the water reservoir 252. For instance, the watervalve 268 is operable to evacuate water from the water reservoir 252when water levels in the water reservoir 252 are too high.

Each water dispensation line 262 leads from the water reservoir 252 toonboard the FCV 100. On each water dispensation line 262, in addition tothe requisite piping, the water piping network 254 includes a water pump270 and a water dispenser 272. For each water pump 270 and waterdispenser 272, the water pump 270 is electrically connected to thehandling units 214. Moreover, the water pump 270 is fluidly connected tothe water reservoir 252, and the water dispenser 272 is fluidlyconnected to the water pump 270. Moreover, in addition to being fluidlyconnected to the water pump 270, the water dispenser 272 opens onboardthe FCV 100. The water pump 270 is operable to pump water from the waterreservoir 252 through the water dispenser 272 using electrical energyfrom the handling units 214. The water dispenser 272 is operable todispense water passing through the water dispenser 272. Accordingly, inconjunction with the water dispenser 272, the water pump 270 is operableto dispense water from the water reservoir 252 onboard the FCV 100. Forinstance, the water pump 270 may be operable to dispense water from thewater reservoir 252 into the front compartment 108, into the passengercompartment 106 or into the rear compartment 110, as well as at theexterior 104.

Among other things, it follows that the water pump 266 pumps water fromthe fuel cell stack 202 into the water reservoir 252 using electricalenergy from the batteries 210. Moreover, the water pumps 270 dispensewater from the water reservoir 252 using electrical energy from thebatteries 210.

With the FCV 100 including multiple batteries 210 in the battery system152, the batteries 210 include a motor battery 210A and a complementarybattery 210B. The motor battery 210A is dedicated to handling theelectrical energy loads on the battery system 152 from the motor system156 and, in particular, those from the motor 206. The complementarybattery 210B is dedicated to handling the remaining electrical energyloads on the battery system 152 from the remainder of the vehiclesystems 120 besides the motor system 156, including those from theenergy system 130, including those from the fuel cell system 150, thosefrom the auxiliary systems 134 and those from the water system 136.

The FCV 100 includes multiple packaging spaces for housing the vehicleelements of the vehicle systems 120. Among the packaging spaces, the FCV100 includes the chassis 114, including underneath the passengercompartment 106, underneath the front compartment 108 and underneath therear compartment 110. Also among the packaging spaces, above the chassis114, the FCV 100 includes the front compartment 108 and the rearcompartment 110. The vehicle elements housed in the chassis 114 arelower (i.e., closer to the ground) than the vehicle elements housed inthe front compartment 108 and the rear compartment 110. Equally, thevehicle elements housed in the front compartment 108 and the rearcompartment 110 are higher (i.e., further from the ground) than thevehicle elements housed in the chassis 114.

As noted above, the FCV 100 includes the fuel cell stack 202 among theenergy elements of the fuel cell system 150, the fuel tanks 220 amongthe energy elements of the fuel tank system 154, and the motor 206 amongthe propulsion elements of the motor system 156. The fuel cell stack 202and the motor 206 are housed in the chassis 114. Specifically, the fuelcell stack 202 is housed in the chassis 114 underneath the passengercompartment 106, and the motor 206 is housed in the chassis 114underneath the rear compartment 110. In relation to the fuel cell stack202, the FCV 100 may include a support rack mounted to the chassis 114underneath the passenger compartment 106, and the fuel cell stack 202may be mounted to the support rack. In relation to the motor 206, theFCV 100 may include a motor cradle mounted to the chassis 114 underneaththe rear compartment 110, and the motor 206 may be mounted to the motorcradle. The fuel tanks 220 are housed above the chassis 114.Specifically, the fuel tanks 220 are housed above the chassis 114 in therear compartment 110. In relation to the fuel tanks 220, the FCV 100 mayinclude a support rack housed in the rear compartment 110, and, with thesupport rack mounted to or otherwise supported by the chassis 114, thefuel tanks 220 may be mounted to the support rack.

Moreover, in relation to reclaiming water from the fuel cell stack 202,the FCV 100 includes the water collector 250 and the water reservoir 252among the water elements of the water system 136. For purposes ofcollecting water from the fuel cell stack 202, the fuel cell stack 202and the water collector 250 share the same packaging space in the FCV100. Accordingly, like the fuel cell stack 202, the water collector 250is housed in the chassis 114. Specifically, the water collector 250 ishoused in the chassis 114 underneath the passenger compartment 106. Inrelation to the fuel cell stack 202 and the water collector 250, the FCV100 may include a common support rack mounted to the chassis 114underneath the passenger compartment 106, and the fuel cell stack 202and the water collector 250 may be mounted to the common support rack.On the other hand, for purposes of storing water from the fuel cellstack 202, the fuel cell stack 202 and the water reservoir 252 sharedifferent packaging spaces in the FCV 100. Accordingly, unlike the fuelcell stack 202, the water reservoir 252 is housed above the chassis 114.Specifically, the water reservoir 252 is housed above the chassis 114 inthe front compartment 108. In relation to the water reservoir 252, theFCV 100 may include a support stand housed in the front compartment 108,and, with the support stand mounted to or otherwise supported by thechassis 114, the water reservoir 252 may be mounted to the supportstand. Although the water reservoir 252, as shown, is housed above thechassis 114 in the front compartment 108, it will be understood thatthis disclosure is applicable in principle to otherwise similar vehiclesincluding the water reservoir 252 housed otherwise above the chassis114, including in the rear compartment 110 or between the passengercompartment 106 and the rear compartment 110.

Among other things, it follows that, in the FCV 100, the water reservoir252 is housed away from the fuel cell stack 202. Moreover, with the fuelcell stack 202 housed in the chassis 114, and the water reservoir 252housed above the chassis 114 in the front compartment 108, the waterreservoir 252 enjoys a more spacious packaging space in the FCV 100 thanthe fuel cell stack 202. Specifically, with the FCV 100 including themotor 206 in the chassis 114 in place of an engine in the frontcompartment 108, the front compartment 108 is more spacious than thechassis 114.

Taking advantage of the more spacious packaging space in the FCV 100,the water reservoir 252 is rightsized for storing water from the fuelcell stack 202. For instance, the operation of the FCV 100 may bemodeled in terms of reclamation of water from the fuel cell stack 202and dispensation of water over time, and the water reservoir 252 may berightsized based on the modeling. Specifically, for purposes ofreclaiming water from the fuel cell stack 202 for dispensation, waterfrom the fuel cell stack 202 is a replenishing but ultimately limitedresource that ideally is not wasted. In recognition of this principle,with respect to storing water from the fuel cell stack 202, the waterreservoir 252 is sized large enough to inhibit water levels in the waterreservoir 252 not only from becoming too low, but also from becoming toohigh. Specifically, the water reservoir 252 is sized large enough toinhibit water levels in the water reservoir 252 from becoming too highas the water pump 266 is operated to pump water from the fuel cell stack202 into the water reservoir 252 and the water pumps 270 are operated todispense water from the water reservoir 252 over time. By sizing thewater reservoir 252 large enough to inhibit water levels in the waterreservoir 252 from becoming too high, water from the water reservoir 252is not wastefully evacuated.

Among other things, it also follows that, in the FCV 100, the waterreservoir 252 is housed higher than the fuel cell stack 202. As notedabove, in the fuel cell stack-powered implementation, absent the fuelcell stack 202 generating surplus electrical energy when the motor 206powers the wheels 118, the batteries 210 principally store electricalenergy from the motor 206 when the motor 206 generates electrical energyusing the wheels 118, and consequently retards the wheels 118.Accordingly, the fuel cell stack-powered implementation raises issuesconcerning using electrical energy from the batteries 210 and, inparticular, issues concerning electrical energy levels in the batteries210 becoming too low when electrical energy from the batteries 210 isused on an on-demand basis. At the same time, one, some or all of thewater pumps 270 are operated to dispense water from the water reservoir252 on an on-demand basis. Likewise, in association with dispensingwater from the water reservoir 252, one, some or all of the water pumps270 use electrical energy from the batteries 210 on an on-demand basis.On the other hand, the water pump 266 is operated to pump water from thefuel cell stack 202 into the water reservoir 252 on a time-selectivebasis. Likewise, in association with pumping water from the fuel cellstack 202 into the water reservoir 252, the water pump 266 useselectrical energy from the batteries 210 on a time-selective basis.

With the water reservoir 252 housed higher than the fuel cell stack 202,from the perspective of the fuel cell stack 202, the water pump 266pumps water from the fuel cell stack 202 into the water reservoir 252against gravity. With the water pump 266 having pumped water from thefuel cell stack 202 into the water reservoir 252 against gravity, waterin the water reservoir 252 has gravitational potential energy. Moreover,with water in the water reservoir 252 having gravitational potentialenergy, the water pumps 270 dispense water from the water reservoir 252under assistance from gravitational potential energy of water in thewater reservoir 252. Accordingly, in association with dispensing waterfrom the water reservoir 252 under assistance from gravitationalpotential energy of water in the water reservoir 252, the water pumps270, although using electrical energy from the batteries 210 on anon-demand basis, use commensurately less electrical energy from thebatteries 210. Moreover, in association with pumping water from the fuelcell stack 202 into the water reservoir 252 against gravity, the waterpump 266, although using commensurately offsetting electrical energyfrom the batteries 210, only uses electrical energy from the batteries210 on a time-selective basis. Accordingly, notwithstanding the waterpumps 270 being operated to dispense water from the water reservoir 252on an on-demand basis, the water pump 266 is operated to pump water fromthe fuel cell stack 202 into the water reservoir 252 on a time-selectivebasis to inhibit electrical energy levels in the batteries 210 frombecoming too low.

In relation to the heat exchanger 236 rejecting heat from the fuel cellstack 202, with the heat exchanger 236 housed in the front compartment108, a water dispensation line 262A leads to the front compartment 108.On the water dispensation line 262A, the water piping network 254includes a water pump 270A and a water applicator 272A for the heatexchanger 236. The water pump 270A is electrically connected to thehandling units 214. Moreover, the water pump 270A is fluidly connectedto the water reservoir 252, and the water applicator 272A is fluidlyconnected to the water pump 270A. Moreover, in addition to being fluidlyconnected to the water pump 270A, the water applicator 272A opens intothe front compartment 108 about the heat exchanger 236. The water pump270A is operable to pump water from the water reservoir 252 throughwater applicator 272A using electrical energy from the handling units214. The water applicator 272A is operable to spray, mist, sprinkle orotherwise apply water passing through the water applicator 272A.Accordingly, in conjunction with the water applicator 272A, the waterpump 270A is operable to apply water from the water reservoir 252 ontothe heat exchanger 236. Water on the heat exchanger 236 vaporizes inairflow across the heat exchanger 236. Accordingly, when water from thewater reservoir 252 is applied onto the heat exchanger 236, the heatexchanger 236 becomes operable to super-normally reject heat fromcoolant passing through the heat exchanger 236 to airflow across theheat exchanger 236. Moreover, as the product of super-normally rejectingheat from coolant passing through the heat exchanger 236 to airflowacross the heat exchanger 236, the heat exchanger 236 becomes operableto super-normally reject heat from the fuel cell stack 202.

In terms of electrical energy and water, as well as heat, output fromthe fuel cell stack 202 is variable. From an electrochemical standpoint,output from the fuel cell stack 202 is commensurate with the amounts offuel and oxygen in air combined by the electrochemical reaction. At thesame time, from a broader operational standpoint, for purposes ofpromoting the electrochemical reaction, the heat exchanger 236, inassociation with rejecting heat from the fuel cell stack 202, is taskedwith balancing heat from the fuel cell stack 202 with heat rejected fromthe fuel cell stack 202. When the heat exchanger 236 counter-balancesheat from the fuel cell stack 202 with heat rejected from the fuel cellstack 202, temperatures in the fuel cell stack 202 are ideal (e.g.,approximately 75 degrees Celsius or otherwise between approximately 60degrees Celsius and approximately 80 degrees Celsius). When the heatexchanger 236 under-balances heat from the fuel cell stack 202 with heatrejected from the fuel cell stack 202, temperatures in the fuel cellstack 202 become too high (e.g., above approximately 80 degreesCelsius). When the heat exchanger 236 over-balances heat from the fuelcell stack 202 with heat rejected from the fuel cell stack 202,temperatures in the fuel cell stack 202 become too low (e.g., belowapproximately 60 degrees Celsius).

As noted above, in the fuel cell stack-powered implementation, the motor206 principally powers the wheels 118 using electrical energy from thefuel cell stack 202. In terms of electrical energy, oftentimes, evenwhen output from the fuel cell stack 202 is already high, still higheroutput from the fuel cell stack 202 would be advantageous. However, inassociation with higher output from the fuel cell stack 202, the heatexchanger 236 sometimes under-balances heat from the fuel cell stack 202with heat rejected from the fuel cell stack 202. When the heat exchanger236 under-balances heat from the fuel cell stack 202 with heat rejectedfrom the fuel cell stack 202, higher output from the fuel cell stack 202is infeasible. However, when the water pump 270A applies water from thewater reservoir 252 onto the heat exchanger 236, and the heat exchanger236 super-normally rejects heat from the fuel cell stack 202, the heatexchanger 236 restoratively counter-balances heat from the fuel cellstack 202 with heat rejected from the fuel cell stack 202. When the heatexchanger 236 restoratively counter-balances heat from the fuel cellstack 202 with heat rejected from the fuel cell stack 202, higher outputfrom the fuel cell stack 202 becomes feasible. Accordingly, the fuelcell stack 202 becomes operable to super-normally generate electricalenergy and water.

Notably, the water pump 270A is selectively operated to apply water fromthe water reservoir 252 onto the heat exchanger 236. Initially, if thewater pump 270A indiscriminately applies water from the water reservoir252 onto the heat exchanger 236, water levels in the water reservoir 252become too low. Moreover, normally, in association with most output fromthe fuel cell stack 202, the heat exchanger 236 counter-balances heatfrom the fuel cell stack 202 with heat rejected from the fuel cell stack202. When the heat exchanger 236 counter-balances heat from the fuelcell stack 202 with heat rejected from the fuel cell stack 202, if thewater pump 270A indiscriminately applies water from the water reservoir252 onto the heat exchanger 236, and the heat exchanger 236super-normally rejects heat from the fuel cell stack 202, the heatexchanger 236 disruptively over-balances heat from the fuel cell stack202 with heat rejected from the fuel cell stack 202. Accordingly, thewater pump 270A is selectively operated to apply water from the waterreservoir 252 onto the heat exchanger 236 to inhibit the heat exchanger236 from under-balancing heat from the fuel cell stack 202 with heatrejected from the fuel cell stack 202.

In an onboard tap water implementation, a water dispensation line 262Bleads to the passenger compartment 106. On the water dispensation line262B, the water piping network 254 includes a water pump 270B, a waterfilter 274 and a water tap 272B. The water pump 270B is electricallyconnected to the handling units 214. Moreover, the water pump 270B isfluidly connected to the water reservoir 252, and the water tap 272B isfluidly connected to the water pump 270B through the water filter 274.Moreover, in addition to being fluidly connected to the water pump 270Bthrough the water filter 274, the water tap 272B opens into thepassenger compartment 106. The water pump 270B is operable to pump waterfrom the water reservoir 252 through the water filter 274 and throughthe water tap 272B using electrical energy from the handling units 214.The water filter 274 is operable to filter water passing through thewater filter 274. The water tap 272B is user-operable to dispense waterpassing through the water tap 272B. Accordingly, in conjunction with thewater filter 274 and the water tap 272B, the water pump 270B is operableto dispense filtered water from the water reservoir 252 into thepassenger compartment 106 for drinking, cooking, washing and the like.

In an onboard power washer implementation, a water dispensation line262C leads to the exterior 104. On the water dispensation line 262C, thewater piping network 254 includes a water pump 270C and a water hookup272C, as well as a high-pressure water hose and nozzle unit 276 typicalof power washers. The water pump 270C is electrically connected to thehandling units 214. Moreover, the water pump 270C is fluidly connectedto the water reservoir 252, and the water hookup 272C is fluidlyconnected to the water pump 270C. Moreover, in addition to being fluidlyconnected to the water pump 270C, the water hookup 272C opens at theexterior 104. Moreover, the water hose and nozzle unit 276 is fluidlyconnected to the water hookup 272C. The water pump 270C is operable topump water from the water reservoir 252 through the water hookup 272Cusing electrical energy from the handling units 214. The water hookup272C is operable to dispense water passing through the water hookup 272Cat the exterior 104. The water hose and nozzle unit 276 is user-operableto dispense water passing through the water hose and nozzle unit 276under pressure. Accordingly, in conjunction with the water hookup 272Cand the water hose and nozzle unit 276, the water pump 270C is operableto dispense water from the water reservoir 252 under pressure at theexterior 104 for power washing the FCV 100 and items in the environmentsurrounding the FCV 100.

The FCV 100 is equipped, in operation, to perform vehicle functions onbehalf of the FCV 100, and thereby satisfy corresponding vehicle demandson behalf of the FCV 100. Specifically, the energy system 130 isoperable to perform energy functions, and thereby satisfy correspondingenergy demands, the propulsion system 132 is operable to performpropulsion functions, and thereby satisfy corresponding propulsiondemands, the auxiliary systems 134 are operable to perform auxiliaryfunctions, and thereby satisfy corresponding auxiliary demands, and thewater system 136 is operable to perform water functions, and therebysatisfy corresponding water demands.

The energy demands may include any combination of demands to generateelectrical energy, demands to generate water, demands to reject heatfrom the fuel cell stack 202, demands to store electrical energy,including demands to store electrical energy from the fuel cell stack202, and demands to store electrical energy from the motor 206, demandsto condition and otherwise handle electrical energy, and demands tostore and otherwise handle fuel. The propulsion demands may includedemands to power the wheels 118, and demands to generate electricalenergy using the wheels 118, and consequently retard the wheels 118. Anycombination of the energy demands and the propulsion demands may be partof combined energy and propulsion demands, such as demands toregeneratively brake the FCV 100. The auxiliary demands may include anycombination of demands to frictionally brake the FCV 100, demands tosteer the FCV 100 and demands to perform accessory functions. The waterdemands may include any combination of demands to discharge water fromthe water collector 250, demands to reclaim water from the fuel cellstack 202, including demands to pump water from the fuel cell stack 202into the water reservoir 252, demands to evacuate water from the waterreservoir 252, and demands to dispense water from the water reservoir252, including demands to apply water from the water reservoir 252 ontothe heat exchanger 236, demands to dispense filtered water from thewater reservoir 252 into the passenger compartment 106, and demands todispense water from the water reservoir 252 under pressure at theexterior 104.

The operations of a process 300 for operating the FCV 100 under theorchestration of the control module 128 are shown in FIG. 3. Accordingto the process 300, the control module 128 orchestrates the operation ofthe FCV 100.

In operation 302, the control module 128 gathers information about theFCV 100, including the information about the FCV 100 detected by thesensor system 122. In operation 304, the control module 128 evaluatesthe information about the FCV 100, including monitoring for andidentifying vehicle demands. For purposes of identifying vehicle demandsand otherwise evaluating information about the FCV 100 according tooperation 304, the control module 128 may evaluate any combination ofevident and prospective information about the FCV 100, and may identifyany combination of evident and prospective vehicle demands.

In operations 306 and 308, the control module 128 operates the vehiclesystems 120 based on its evaluation of the information about the FCV100. Specifically, when, according to operation 306, the control module128 does not identify a vehicle demand, the control module 128 does notoperate the associated vehicle systems 120. Otherwise, when the controlmodule 128 identifies a vehicle demand according to operation 306, inoperation 308, the control module 128 operates the associated vehiclesystems 120 to satisfy the vehicle demand. For instance, when thecontrol module 128 identifies an energy demand according to operation306, the control module 128 operates the energy system 130 to satisfythe energy demand in operation 308. And, when the control module 128identifies a propulsion demand according to operation 306, the controlmodule 128 operates the propulsion system 132 to satisfy the propulsiondemand in operation 308. Moreover, when the control module 128identifies an auxiliary demand according to operation 306, the controlmodule 128 operates the auxiliary systems 134 to satisfy the auxiliarydemand in operation 308. Moreover, when the control module 128identifies a water demand according to operation 306, the control module128 operates the water system 136 to satisfy the water demand inoperation 308. For purposes of identifying vehicle demands and operatingthe associated vehicle systems 120 to satisfy the vehicle demandsaccording to operations 306 and 308, the control module 128 may operatethe associated vehicle systems 120 on any combination of on-demand basesand time-selective bases.

In both cases, the control module 128 continues to gather informationabout the FCV 100 according to operation 302, and continues to evaluatethe information about the FCV 100 according to operation 304. Followingnot operating the vehicle systems 120, as part of its continuedevaluation of the information about the FCV 100 according to operation304, the control module 128 continues to monitor for vehicle demands inanticipation that previously-unidentified vehicle demands willmaterialize. On the other hand, following operating the associatedvehicle systems 120 to satisfy the vehicle demand according to operation308, as part of its continued evaluation of the information about theFCV 100 according to operation 304, the control module 128 continues toidentify vehicle demands in anticipation that the previously-identifiedvehicle demand will be satisfied. When the previously-identified vehicledemand is satisfied, and the previously-identified vehicle demand isthus no longer identified according to operation 304, the control module128 concludes operating the associated vehicle systems 120.

For purposes of identifying vehicle demands and otherwise evaluatinginformation about the FCV 100 according to operation 304, the controlmodule 128 may gather any combination of information about user requestsand information about the operation of the FCV 100. This and otherinformation about the FCV 100 may be detected by the sensor system 122.The information about user requests may include any combination of userinputs requesting powering the wheels 118, user inputs requestingbraking, steering and the like, user inputs requesting accessoryfunctions, including user inputs requesting navigation, and user inputsrequesting water functions, including user inputs requesting dispensingwater from the water reservoir 252. The information about the operationof the FCV 100 may include any combination of the location and motion ofthe FCV 100, the movement of the wheels 118, and the operationalstatuses of one, some or all of the vehicle systems 120. The operationalstatuses of the vehicle systems 120 may include any combination ofoperation of the vehicle systems 120 and associated electrical energyloads on the batteries 210 from the vehicle systems 120. Moreover, withrespect to the energy system 130, the operational statuses of thevehicle systems 120 may include any combination of output from the fuelcell stack 202, including any combination of electrical energy from thefuel cell stack 202, water from the fuel cell stack 202, heat from thefuel cell stack 202 and temperatures in the fuel cell stack 202, heatrejected from the fuel cell stack 202 by the heat exchanger 236 andelectrical energy levels in the batteries 210. Moreover, with respect tothe propulsion system 132, the operational statuses of the vehiclesystems 120 may include electrical energy from the motor 206. Forinstance, with respect to the water system 136, the operational statusesof the vehicle systems 120 may include any combination of water levelsin the water collector 250 and water levels in the water reservoir 252.

According to the process 300, as part of orchestrating the operation ofthe FCV 100, the control module 128 orchestrates the operation of watersystem 136. According to one aspect of the operation of water system136, as noted above, the water pump 270A is selectively operated toapply water from the water reservoir 252 onto the heat exchanger 236 toinhibit the heat exchanger 236 from under-balancing heat from the fuelcell stack 202 with heat rejected from the fuel cell stack 202.Likewise, according to operations 306 and 308, the control module 128selectively operates the water pump 270A to apply water from the waterreservoir 252 onto the heat exchanger 236 to inhibit the heat exchanger236 from under-balancing heat from the fuel cell stack 202 with heatrejected from the fuel cell stack 202.

Specifically, demands to apply water from the water reservoir 252 ontothe heat exchanger 236 correspond to the heat exchanger 236under-balancing heat from the fuel cell stack 202 with heat rejectedfrom the fuel cell stack 202 during operation of the fuel cell stack202. When the control module 128 identifies a demand to apply water fromthe water reservoir 252 onto the heat exchanger 236 according tooperation 306, in operation 308, the control module 128 operates thewater pump 270A to satisfy the demand to apply water from the waterreservoir 252 onto the heat exchanger 236. Otherwise, when, according tooperation 306, the control module 128 does not identify a demand toapply water from the water reservoir 252 onto the heat exchanger 236,the control module 128 does not operate the water pump 270A.

At the same time, as noted above, normally, in association with mostoutput from the fuel cell stack 202, the heat exchanger 236counter-balances heat from the fuel cell stack 202 with heat rejectedfrom the fuel cell stack 202. Accordingly, by extension, demands toapply water from the water reservoir 252 onto the heat exchanger 236correspond to higher output from the fuel cell stack 202. Demands forhigher output from the fuel cell stack 202, in turn, correspond to anycombination of user inputs requesting powering the wheels 118 and/oruser inputs requesting navigation associated with demands to power thewheels 118 (e.g., in relation to accelerating the FCV 100, maintainingthe speed of the FCV 100 on level or uphill ground, etc.), insufficientelectrical energy from the fuel cell stack 202 for the motor 206 topower the wheels 118 and the like. Additionally, or alternatively,demands for higher output from the fuel cell stack 202 correspond to lowelectrical energy levels in the batteries 210. Additionally, oralternatively, demands for higher output from the fuel cell stack 202correspond to high electrical energy loads on the batteries 210. Whenthe control module 128 identifies a demand for higher output from thefuel cell stack 202 according to operation 306, in operation 308, thecontrol module 128 operates the fuel cell stack 202 for higher output tosatisfy the demand for higher output from the fuel cell stack 202.

Meanwhile, demands to evacuate water from the water reservoir 252correspond to high water levels in the water reservoir 252. Byextension, demands to evacuate water from the water reservoir 252correspond to any combination of operation of the water pump 266 to pumpwater from the fuel cell stack 202 into the water reservoir 252, no orlow operation of the water pumps 270 to dispense water from the waterreservoir 252, including no or low operation of the water pump 270A toapply water from the water reservoir 252 onto the heat exchanger 236,and the like. As noted above, for purposes of reclaiming water from thefuel cell stack 202 for dispensation, water from the fuel cell stack 202is a replenishing but ultimately limited resource that ideally is notwasted. When the control module 128 identifies a demand to evacuatewater from the water reservoir 252 according to operation 306, inoperation 308, the control module 128 operates the water valve 268 tosatisfy the demand to evacuate water from the water reservoir 252. Whenthe control module 128 operates the water valve 268 to satisfy thedemand to evacuate water from the water reservoir 252 according tooperation 308, water from the fuel cell stack 202 is wasted. Otherwise,when, according to operation 306, the control module 128 does notidentify a demand to evacuate water from the water reservoir 252, thecontrol module 128 does not operate the water valve 268, and water fromthe fuel cell stack 202 is not wasted.

Among other things, if follows that when water levels in the waterreservoir 252 are high, demands to evacuate water from the waterreservoir 252 tend to materialize when demands for higher output fromthe fuel cell stack 202, and corresponding demands to apply water fromthe water reservoir 252 onto the heat exchanger 236, do not materialize.According to another aspect of the operation of water system 136, thecontrol module 128 seeks to take advantage of water in the waterreservoir 252 notwithstanding not identifying a demand for higher outputfrom the fuel cell stack 202, or a corresponding demand to apply waterfrom the water reservoir 252 onto the heat exchanger 236, according tooperation 306. Specifically, when, according to operation 304, thecontrol module 128 identifies high water levels in the water reservoir252, and identifies a corresponding demand to evacuate water from thewater reservoir 252 according to operation 306, the control module 128,in operation 308, instead of operating the water valve 268 to satisfythe demand to evacuate water from the water reservoir 252, increaseselectrical energy loads on the batteries 210. When electrical energyloads on the batteries 210 are increased, demands for higher output fromthe fuel cell stack 202, and corresponding demands to apply water fromthe water reservoir 252 onto the heat exchanger 236, tend tomaterialize, whereupon demands to evacuate water from the waterreservoir 252 dematerialize.

With respect to increasing electrical energy loads on the batteries 210,as part of its continued evaluation of the information about the FCV 100according to operation 304, the control module 128 monitors for andidentifies latent vehicle demands. When the control module 128identifies a latent vehicle demand according to operation 304, inoperation 308, the control module 128 operates the associated vehiclesystems 120 to satisfy the latent vehicle demand using electrical energyfrom the batteries 210. For instance, as part of its continuedevaluation of the information about the FCV 100 according to operation304, the control module 128 may monitor for and identify latent demandsto pump water from the fuel cell stack 202 into the water reservoir 252.When the control module 128 identifies a latent demand to pump waterfrom the fuel cell stack 202 into the water reservoir 252 according tooperation 304, in operation 308, the control module 128 may operate thewater pump 266 to satisfy the latent demand to pump water from the fuelcell stack 202 into the water reservoir 252 using electrical energy fromthe batteries 210. Additionally, or alternatively, when, according tooperation 306, the control module 128 does not identify a vehicle demandto perform a vehicle function, the control module 128, notwithstandingno vehicle demand to perform the vehicle function, operates theassociated vehicle systems 120 to perform the vehicle function usingelectrical energy from the batteries 210.

When, in association with increasing electrical energy loads on thebatteries 210, the control module 128 identifies a demand for higheroutput from the fuel cell stack 202 according to operation 306, inoperation 308, the control module 128 operates the fuel cell stack 202for higher output to satisfy the demand for higher output from the fuelcell stack 202. Moreover, when, in association with operating the fuelcell stack 202 for higher output, the control module 128 identifies ademand to apply water from the water reservoir 252 onto the heatexchanger 236 according to operation 306, in operation 308, the controlmodule 128 operates the water pump 270A to satisfy the demand to applywater from the water reservoir 252 onto the heat exchanger 236.Moreover, when, in association with operating the water pump 270A tosatisfy the demand to apply water from the water reservoir 252 onto theheat exchanger 236, the control module 128 does not identify a demand toevacuate water from the water reservoir 252 according to operation 306,the control module 128 does not operate the water valve 268, and waterfrom the fuel cell stack 202 is not wasted.

With reference once again to FIG. 1, as noted above, the processors 124,the memory 126 and the control module 128 together serve as a computingdevice whose control module 128 orchestrates the operation of the FCV100. The control module 128 may be a global control module thatorchestrates the global operation of the FCV 100, including but notlimited to the operation of the vehicle systems 120. Relatedly, as partof a central control system, the FCV 100 may include a global controlunit (GCU) to which the control module 128 belongs. Additionally, oralternatively, the control module 128 may be a power control module thatorchestrates the operation of the energy system 130 and the propulsionsystem 132, as well as the auxiliary systems 134 and the water system136. Relatedly, the FCV 100 may include a power control unit (PCU) towhich the control module 128 belongs. Although the FCV 100, as shown,includes one control module 128, it will be understood that thisdisclosure is applicable in principle to otherwise similar vehiclesincluding multiple control modules 128.

The processors 124 may be any components configured to execute any ofthe processes described herein or any form of instructions to carry outsuch processes or cause such processes to be performed. The processors124 may be implemented with one or more general purpose or specialpurpose processors. Examples of suitable processors 124 includemicroprocessors, microcontrollers, digital signal processors or otherforms of circuitry that execute software. Other examples of suitableprocessors 124 include without limitation central processing units(CPUs), array processors, vector processors, digital signal processors(DSPs), field programmable gate arrays (FPGAs), programmable logicarrays (PLAs), application specific integrated circuits (ASICs),programmable logic circuitry or controllers. The processors 124 mayinclude at least one hardware circuit (e.g., an integrated circuit)configured to carry out instructions contained in program code. Inarrangements where there are multiple processors 124, the processors 124may work independently from each other or in combination with oneanother.

The memory 126 is a non-transitory computer readable medium. The memory126 may include volatile or nonvolatile memory, or both. Examples ofsuitable memory 126 include random access memory (RAM), flash memory,read only memory (ROM), programmable read only memory (PROM), erasableprogrammable read only memory (EPROM), electrically erasableprogrammable read only memory (EEPROM), registers, magnetic disks,optical disks, hard drives or any other suitable storage medium, or anycombination of these. The memory 126 includes stored instructions inprogram code. Such instructions are executable by the processors 124 orthe control module 128. The memory 126 may be part of the processors 124or the control module 128, or may be communicatively connected theprocessors 124 or the control module 128.

Generally speaking, the control module 128 includes instructions thatmay be executed by the processors 124. The control module 128 may beimplemented as computer readable program code that, when executed by theprocessors 124, executes one or more of the processes described herein.Such computer readable program code may be stored on the memory 126. Thecontrol module 128 may be part of the processors 124, or may becommunicatively connected the processors 124.

While recited characteristics and conditions of the invention have beendescribed in connection with certain embodiments, it is to be understoodthat the invention is not to be limited to the disclosed embodimentsbut, on the contrary, is intended to cover various modifications andequivalent arrangements included within the spirit and scope of theappended claims, which scope is to be accorded the broadestinterpretation so as to encompass all such modifications and equivalentstructures as is permitted under the law.

What is claimed is:
 1. A system for operating a vehicle, comprising: oneor more processors; and a memory communicably coupled to the one or moreprocessors and storing instructions that when executed by the one ormore processors cause the one or more processors to: operate at leastone fuel cell stack, whereupon a heat exchanger for the at least onefuel cell stack counter-balances heat from the at least one fuel cellstack with heat rejected from the at least one fuel cell stack; operatea water system to pump water from the at least one fuel cell stack intoa water reservoir; and in response to high water levels in the waterreservoir: increase electrical energy loads on at least one batteryoperable to store electrical energy from the at least one fuel cellstack; operate the at least one fuel cell stack for higher output,whereupon the heat exchanger under-balances heat from the at least onefuel cell stack with heat rejected from the at least one fuel cellstack; and operate the water system to apply water from the waterreservoir onto the heat exchanger, whereupon the heat exchangerrestoratively counter-balances heat from the at least one fuel cellstack with heat rejected from the at least one fuel cell stack.
 2. Thesystem of claim 1, wherein the memory further stores instructions thatwhen executed by the one or more processors cause the one or moreprocessors to: identify high water levels in the water reservoir,wherein identifying high water levels in the water reservoir includesidentifying any combination of operation of the water system to pumpwater from the at least one fuel cell stack into the water reservoir andno or low operation of the water system to dispense water from the waterreservoir.
 3. The system of claim 1, wherein the response to high waterlevels in the water reservoir is at least one of notwithstanding nodemand for higher output from the fuel cell stack and instead ofoperating the water system to evacuate water from the water reservoir.4. The system of claim 1, wherein increasing electrical energy loads onthe at least one battery includes operating a vehicle system to satisfya latent vehicle demand using electrical energy from the at least onebattery.
 5. The system of claim 1, wherein increasing electrical energyloads on the at least one battery includes operating a vehicle system toperform a vehicle function using electrical energy from the at least onebattery notwithstanding no vehicle demand to perform the vehiclefunction.
 6. The system of claim 1, wherein operating the at least onefuel cell stack for higher output includes operating the at least onefuel cell stack for super-normal output.
 7. A method for operating avehicle, comprising: operating at least one fuel cell stack, whereupon aheat exchanger for the at least one fuel cell stack counter-balancesheat from the at least one fuel cell stack with heat rejected from theat least one fuel cell stack; operating a water system to pump waterfrom the at least one fuel cell stack into a water reservoir; and inresponse to high water levels in the water reservoir: increasingelectrical energy loads on at least one battery operable to storeelectrical energy from the at least one fuel cell stack; operating theat least one fuel cell stack for higher output, whereupon the heatexchanger under-balances heat from the at least one fuel cell stack withheat rejected from the at least one fuel cell stack; and operating thewater system to apply water from the water reservoir onto the heatexchanger, whereupon the heat exchanger restoratively counter-balancesheat from the at least one fuel cell stack with heat rejected from theat least one fuel cell stack.
 8. The method of claim 7, furthercomprising: identifying high water levels in the water reservoir,wherein identifying high water levels in the water reservoir includesidentifying any combination of operation of the water system to pumpwater from the at least one fuel cell stack into the water reservoir andno or low operation of the water system to dispense water from the waterreservoir.
 9. The method of claim 7, wherein the response to high waterlevels in the water reservoir is notwithstanding no demand for higheroutput from the fuel cell stack.
 10. The method of claim 7, wherein theresponse to high water levels in the water reservoir is instead ofoperating the water system to evacuate water from the water reservoir.11. The method of claim 7, wherein increasing electrical energy loads onthe at least one battery includes operating a vehicle system to satisfya latent vehicle demand using electrical energy from the at least onebattery.
 12. The method of claim 7, wherein increasing electrical energyloads on the at least one battery includes operating the water system tosatisfy a latent demand to pump water from the at least one fuel cellstack into the water reservoir using electrical energy from the at leastone battery.
 13. The method of claim 7, wherein increasing electricalenergy loads on the at least one battery includes operating a vehiclesystem to perform a vehicle function using electrical energy from the atleast one battery notwithstanding no vehicle demand to perform thevehicle function.
 14. The method of claim 7, wherein operating the atleast one fuel cell stack for higher output includes operating the atleast one fuel cell stack for super-normal output.
 15. A non-transitorycomputer-readable medium for operating a vehicle including instructionsthat when executed by one or more processors cause the one or moreprocessors to: operate at least one fuel cell stack, whereupon a heatexchanger for the at least one fuel cell stack counter-balances heatfrom the at least one fuel cell stack with heat rejected from the atleast one fuel cell stack; operate a water system to pump water from theat least one fuel cell stack into a water reservoir; and in response tohigh water levels in the water reservoir: increase electrical energyloads on at least one battery operable to store electrical energy fromthe at least one fuel cell stack; operate the at least one fuel cellstack for higher output, whereupon the heat exchanger under-balancesheat from the at least one fuel cell stack with heat rejected from theat least one fuel cell stack; and operate the water system to applywater from the water reservoir onto the heat exchanger, whereupon theheat exchanger restoratively counter-balances heat from the at least onefuel cell stack with heat rejected from the at least one fuel cellstack.
 16. The non-transitory computer-readable medium of claim 15,further including instructions that when executed by one or moreprocessors cause the one or more processors to: identify high waterlevels in the water reservoir, wherein identifying high water levels inthe water reservoir includes identifying any combination of operation ofthe water system to pump water from the at least one fuel cell stackinto the water reservoir and no or low operation of the water system todispense water from the water reservoir.
 17. The non-transitorycomputer-readable medium of claim 15, wherein the response to high waterlevels in the water reservoir is at least one of notwithstanding nodemand for higher output from the fuel cell stack and instead ofoperating the water system to evacuate water from the water reservoir.18. The non-transitory computer-readable medium of claim 15, whereinincreasing electrical energy loads on the at least one battery includesoperating a vehicle system to satisfy a latent vehicle demand usingelectrical energy from the at least one battery.
 19. The non-transitorycomputer-readable medium of claim 15, wherein increasing electricalenergy loads on the at least one battery includes operating a vehiclesystem to perform a vehicle function using electrical energy from the atleast one battery notwithstanding no vehicle demand to perform thevehicle function.
 20. The non-transitory computer-readable medium ofclaim 15, wherein operating the at least one fuel cell stack for higheroutput includes operating the at least one fuel cell stack forsuper-normal output.